Stoker furnace



Aug. 28,1923.. 1,466,562 v J. H. ROACH I STOKER FURNACE Filed Dec. 18 1919 3 Sheets-Sheet 1 E Q I ammo/Wm 1 I l I 95 5 JosephHRoach Aug. 28, 1923.

' J. H. ROACH STOKER FURNACE Filed Dec. 18

, 1919 3 Sheets-Sheet 2 1 3mm Joseph HRoach.

Patented Aug. 28, 1923.

entree stares assa PATENT oF icE.

JOSEPH HFROACH, OIE B ROOKLINE, PENNSYLVANIA; WALTER T. ROACH-EXECUTOR 0F SAID JOSEPH H. ROACH, DECEA$ED.

s'roxnn FURNACE.

Application filed December 18, 1919. Serial ITo. 345,816.

To all whom z't may, concern:

Be it known that I, JOSEPH H. ROACH, a citizen of the United States, residing at Brookline, in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvements in Stoker Furnaces, of which the'following is a specification. g

This invention relates to stoker furnaces and has for an object to provide a stoker having improved means for introducing fuel to and regulating it. upon the grate surface, together with means for varying the air pressure supplied to different areas of the ignited fuel.

Referring to the accompanying drawings, which are made a part hereof, and on which similar reference characters indicate similar parts, i Figure 1 is a longitudinal sectional view of a furnace taken through the retort on line 11 of Figure 2,

Figure 2 is a transverse sectional View taken 011 line 2-2 of Figure 1,

Figure 3 is a horizontal sectional view taken on line 83JofFigures 1 and 2,

Figure 4 is a top plan view of a fragment of the grate surface as indicated by arrow 4 at Figure 2-, i f

Figure 5 is a detail sectional view through .the grate surface as: indicated by line 5-5 of Figure 4,

Figure 6 is a top plan view of the rockshaft operating mechanism, 1

Figure 7 is a'view of the rock-shaft operating mechanism in elevation as indicated by arrow 7 at Figure 6, and

Figure 8 is a view ofethe rock-shaft operating mechanism'in end elevation as indicated by arrow 8 at Figure 6.

The improved stoker which forms the subject matter of this application comprises a,

structure adapted to be] installed within furnace walls indicated at 10, such walls being of the usual and, ordinary construction and forming no part of the present invention except as they co-actfwith the firesupporting and moving structure. Within the chamber formed by the walls 10, a frame work is erected, having the. requisite beams for supporting the grate mechanism- Upon the frame work 111 a beam 12 and retort 13 are erected in any approved manner as by casting integral with the frame members 14. Theretort 13 is of general U-shape and inthe bottom is locateda pusher rod 15, having any approved number of pusher blocks a 16- 'secured thereto. The pusher blocks 16 are triangular in general shape, presenting a substantially vertical side to the fuel, ;when the pusher is moving'forward, and an incline to the coal when the pusher is moving 'rearwardly so that the fuel will rideover such pusher blocks on the return stroke.

To supply fuel to the retort 13, to be acted on by thepusher blocks 16, a hopper 17 is provided, communicating with adminher 18 in which is mounted to reciprocate a ram 19. The proportion of the ram 19 to the chamber 18 is such that at its rearward limit it opens the communication from the hopper 17, permitting the fuel to fall into the chamber 18, and as the ram 19 moves forward it moves the fuel from the chamber 18 into the retort 13 and simultaneously closes communication with the hopper 17. A

To actuate the ram, a cylinder and piston 20are provided, the piston having a piston rod 21 located directly in the rear of the ram :19 and preferably below the center of such ram, in position to substantiallybala-nce the load.

The lower wall of the chamber 18 is pro vided with a slot 22 and'a pintle 23 carried by the ram 19 extends downwardlythrough preferably in the form of annular collars 29.

Upon opposite sides of the frame work 14 of the retort Brock-shafts 30 are journaled and are provided with arms'31 having bifurcated extremities engaging upon the engaging member 28 and between the collars 29. The bifurcated extremities are provided with heads 32 of lesser. diameter than the interval between the collars 29 and adjustable tiller blocks 33 are interposed, upon either side selectively of the heads 32, to vary the stroke of the arms 31 and therefore the amplitude of oscillation of the rockshatts 30.

At Figure 6 is shown diagran'unatically the mov ment for rocking the rock-shaft 30. It will be seen that as the pintle 23 moves from the position shown in full lines to the position 22-5, the levers 27 have been swung to the limit of their movement to the position 27. As the pintle 9'3 continues too-the opposite limit of its movement at 23 the arms 27 are again moved back to full lineposition, so that the levers 27 move through a complete cycle of movement at eachi'orward or rearward movement of the ram 19 carrying the pintle 23. i

The re l-z-sha'tt 30 is provided throughout a part, or parts, or its entire length, as the grate surface may require, witha radially extending rib 34:, enga 'ing notches 35 on the underside of certain grate bars 36, each resting at one end on bearing edge 37 of the frame and at the other end on the bearer bar 38. The grate-bars are caused to slide in the direction of their length on said supports and at the same time are made to rise and fall to a limited extent by the rocking motion of rib fill the grate bars employed E112 be oi the type disclosed at 36- it the conditions of operation and the fuel make it desirable but under ordinary conditions stationary crate bars 39 are employed in. association with the movable grate bars 36 'ihese stationary grate bars bcar, but do not slide,upon 1st, being held by the lugs 40, and

the frame necessary o i both stationaiy and movable bars in the same combination.

i or use with. certain grades of iel and for certain combustion requirements, slicer bars 41 are l o employed The slicer bars when used. z ruled with bosses c "w ng; later-i extending lugs 42 on the posed brrs uhich may be either in F sta ry and with rocl-:--sha"'t draw .i especially at bar il is provided with below thediars andhv pirotally connected upon the rock-shaft.

any approved it is obvious that as the rock-shaft is oscillated by the mechanism hereinbeifore described the movable grate bars engaging the rib 34; will reciprocate and the slicer bars will rise and fall to and from the dotted position shown at Figure 2.

To accommodate the slicer bars the adjacent grate bars 39" are recessed as shown more particularly at Figure 4. Preferably these recessed bars are stationary and the recess is struck upon a curved line to correspond to the are or" movement oi? the slicer bar as indicated at the point 46 at Figure 53.

All of the bar 36, and 39 are provided with ribs (see Figure 5) upon 0 posite sides and the ribsof each bar engage against the ribs of its juxtaposed bars. By this means the fire supporting surface is divided into areas, the one dis posed above the central air duct au l adapted to discharge air through the tuyere-openings 48 into the fuel immediately overlying the retort 13. The other area located over the encircling air duct 49 is adapted to discharge air through the intervals 50 between the several grate bars and upon opposite sides of the slicer bars at. l tiis obvious therefore that by supplying air underdii ferent pressures to the air duct at? and the duct 49 the different areas oi the ignited fuel may be subjected to ditlereut air pressures. As the green fuel, when first introduced into the area of ignition. requires for coking a greater amount of air or air under greater pressure than is required to support combustion atter coking. it is desi able to supply air under greater pressure to the air duct 47 than the iluctl-fl. For this purpose the air duct 47 is in communication with the trunk-duct 51 receivingair from any usual, ordinary or convenient source of air supply. The duct 49 is in communication with or a continuation of a l1GE(lGl-ClUC-ll 52 and the passage or" air from the trunk duct to the header-duct is controlled by means ot a valve 5 -3 having auy convenient and approved means for ma-uipulatiue; as the rod 5 1-, EJI'QVhlG/l with a. hand-hold Ry regulating "the orifice controlled by th valve 53 the relzu tion of the p"essure and. volume between the air in ducts V7 and duct 1-9 may be conl'rollcd as found desirable.

At the outer or lower sides of the grate surface, ash dumps 56 are employed carried by sha't'ts 57, actuated in any ap; 'ovd manner and dumping into ash pits on in the trunk duct 51 a valve 59 is provided which may be of any usual and ordinary type here shown as a butterfly valve mauually operable in any usual and ordinary manner here shown as by the use of the crank arm 60.

In operation the ignited'fuel, upon the fuel surface, 18 replenished by introducing llll green fuel into the hopper 17 and supplying motive fluid tothe cylinder 20." The cylinder 20, with its piston, acts in the usual manner of cylinders andpistonsfto advance the ram 19 and the pushers 16. The advance of the ram andthe pushers 16 also oscillates the rock-shafts30 to reciprocate the movable grate bars 36, ifjany are employed, and oscillate the slicer bars 41, if any are employed. It will be noted that the levers 27, being'moved through a complete cycle of movement at each movement of the ram, the rock-shafts 30 are likewise oscillated through a complete cycle of move ment, that is to say, oscillated to the limit of their movement in both directions, The oscillation of the rock shafts 30, to the limit of their movement in both directions, moves the movable grate bars and slicer bars, when employed, through a complete cycle of their movement, so that at either limit of movement of the ram 19 the fuel supporting surface is in normal condition with the slicer bars flush with the top of the grate surface and the movable grate bars returned to normal position. This feature is highly important in view of the fact that the rapidity of feed of the furnace. is determined by pauses of the rain and pusher at each end of the stroke, the movement in each direction being a rapid 1novement. The slicer bars and movable grate bars are, therefore, moved quickly to perform their functions of agitate normal osition to prevent the said bars from being burned out by remaining elevated out of normality and thus extendim;- into the incandescent mass. 7

While the ribs 46', upon the several grate bars, maintain proper division between the grate areas of low air pressure and high air pressure, even when the movable grate bars and slicer bars are out of normality, it is nevertheless desirable that, for the proper and complete maintenance of such division, the grate surface and tuyere surface be maintained at normal through as large a portion of the time as'possible. This desideratum also makes the double action of the grate bars and slicer bars an important feature.

y the use of the low pressure ducts 49 upon opposite sides of the high pressure duct 47 communicating with I each other through the cross duct and the header duct 52, it is obvious that the pressure in the two low pressure areas will be balanced at all times. The control of the air by the valves 58 and 59 is such that the air is not only balanced in the low pressure ducts, but the pressure in both ducts may be regulatedby the proper manipulation of the valves in suring the desirable air pressure and volume upon the different areas of'the combustion surface.

. Having thus described my said invention,

1 what I claim as new and: desire to secure by retort havingindependent sets of air passages supplying air to the fuel supporting surface, a high pressure air duct disposed beneath the retort and communicating with the air passages supplying air'to said retort,

alow pressure air duct entirely surrounding and receiving air from the high pressure air duct and supplying air to the air passages of the grates anda single valve controlling communication between the high and low pressure air ducts, substantially as set forth.

3. A stoker furnace comprising a retort. grates extending'laterally therefrom in op posite directions, a high pressure air duct beneath the retort for supplying air thereto and low pressure air ducts beneath the grates for supplying air thereto, said high and low pressure ducts being separated by a wall of single thickness comprising sides and ends and the rear end of thehigh pressure duct ing the ignited mass, and are returned to being movable to provide an adjustable communicationbetwecn the high pressure and low pressure ducts, substantially as set forth. 4. In a stoker furnace a retort, grates extending laterallytherefrom in opposite directions, said grates comprising fixed and movable grate bars, supports for'said retort and. grates extending transversely of the furnace chamber, means located on said transverse supports for operating said movable grate bars, a high pressure duct beneathsaid'retort providing a high pressure area in the furnace, a low-pressure duct surrounding said high pressure duct and supplying air to said grates to provide low pressure areas in the furnace, each of said ducts having side and end walls and the space const tuting air ducts below the transverse supports being otherwise free and the rear end wall of the high pressure duct being adjustable to regulate the passage from the high pressure duct to the low pressure ducts, substantially as set forth.

5. In a sto rerfurnace, a grate comprising movable bars, stationary bars and slicer bars interposed between certain of the stationary bars said' slicer bars bein aivotallv sunv g l g ported by aoyacent stationary bars, sun

stantially as set forth.

6. In a furnace, fuel-supporting means coinprisinga high pressure area and a plurality of low'pr'essure areas separated there- 2y, independent sets of air passages -'supply ing air to the different areas, a high pressure air duct for supplying air to the intermediate set of air passages, a 10W pressure duet for supplying air to the sets of air passages separated by the first set, and a single valve leading from the high pressure duct to the low pressure duct, substantially as set forth.

.& 1,466,562

In Witness whereof I have hereunto set my hand and seal at Philadelphia, Pa, this 15th day of December, A. 1)., nineteen hundred and nineteen.

JOSEPH H. ROAGH. [L. s.] Witnesses I F RED GREEN. WV. NELSON J. WVEsT. 

